n68 



A MANUAL OF AMKKICAN LAND SHELLS. 



ftunislied with two white, acute dentich's; on tbe right margin is 

 phiced a white, subper])eudicular, extended lamina. Greater diameter 

 13, lesser 11"""; height, 7i""". 



Helix vcntrosula, Pfpuffer, Proc. Zool. Soc, 1845, 131; Mon. Hel. Viv., i, 417; in 

 Chk.mnitz, ed. 2, i, 373 (1840), pi. Ixv, figs. 5, G (1849).— Reeve, Con. Icon., 

 No. 687 (185':2).— W. G. Binney, Terr. Moll., iv, 73, pi. Ixsvii, fig. 14; L. & 

 Fr.-W. Sli., i, 92. fig. 1(54 (IH(;9).— Crosse nnd Fischer, Moll. Mex. et Gnat., 

 274 (1870). 



Da'daloeliila reiilroiiula. T\:\'0N, Am. Jouni. Conch., iii, 63 (1867). 



Fohigiira ventrosiiht, W. (J. Binney, Terr. Moll., v, 369. 



A Mexicaii species, found also in the Texas Subregiou. 

 Jaw strongly arcuate, of uniform width, ends blunt, anterior surface 

 with 8 broad ribs, crenulating both margins (see Fig. 301, p. 360). 

 Lingual membrane with 93 rows of 24-1-24 teeth each, 9 laterals; 

 I'lG 401. centrals tricuspid, the side 



cusps very small; laterals of 

 same shape, but bicuspid; 

 marginals with one inner, 



Lingual dentition of p. ren«rosM«a. obliqUC, bluutly bifid Cut- 



ting point and one smaller outer cutting point. 



Polygyra Bliiidsi, Pfeiffer. 



Shell narrowly umbilicated, depressed, delicately striate, brownish 

 ^'J^o^. horn-color, diaphanous, thin, shining; spire slightly elevated; 

 whorls 5, flattened, the last deflected at the aperture, more 

 convex and constricted below; umbilicus pervious; aperture 

 p.Hindsi. very oblique, lunate, ringent; peristome slightly reflected, its 

 terminations converging, joined by a triangular, tooth like, two-forked 

 callus, the right-hand margin with one subvertical lamina, the columel- 

 lar margin with tv. o acute denticles. Greater diameter 8, lesser 7""^; 

 height, 4^'""'. 



EeHx Eindsi, Pfeiffer, in Proc. Zool. Soc, 1845, 132; Mon. IIcl. Viv., i.416; in 

 Chemnitz, ed. 2, i, 373, tab. Ixv, figs. 7, 8. — Keeve, Con. Icon., 712 

 (1852).— Gould, in Terr. Moll., iii, 17.— W. G. Binney, Terr. Moll., iv, 92, 

 pi. Ixxviii, figs. 5, 6, 8.— L. & Fr.-W. Sli., 93, fig. 167 (1869).— Fischer and 

 Crosse, Moll. Mex. et Gnat., 273 (1876). 



Dcrdalochila Hhidsi, Tryon, Am. Jonrn. Couch., iii, 63 (1867). 



PoUjdiira HimM, W. G. Bixney, Terr. Moll., v, 269. 



In the Texan Subregiou, in Texas and Mexico. 

 Animal not observed. 



